Fuse.



FUSE. APfLICAKTl01" FlLED MAY 8, |912- RENEWED JAN. 2

a, 1915. I Patente Aug. 17, 1915.

' wlT'NEssEs INVENTOR UNiTED STATES PATENT oFFIoE.

ALBERT F. DAUM, F PITTSBURGH, PENNSYLVANIA.

FUSE.

Specification of Letters Patent.

Patented Aug. 1v,4 1915.

Application led May 8, 1912, Serial No. 695,868. Renewed January 28, 1915. Serial No. 4,851.

To all wltom t concern:

Be it known that I, ALBERT F. DAUM, a

citizen of the" United States, residing at.l

Pittsburgh, in the county of Allegheny and *State of Pennsylvania, have invented new and luseful Improvements in Fuses, of which the following is a specification.

My invention relates to improvements in fuses and has particular relation to fuses designed for employment in connection with cut-out blocks and switch-boards, and more particularly known as plug fuses.

The objects of my invention are to provide a fuse of this type which can be readily refilled after being blown; which is formed with a minimum.number of parts.; which may, if desired, beprovided with a detecting mechanism;.which is simple and eiicient in operation, Vdurable in construction, and which can be manufactured at a relatively low cost. l

To these and other ends, the nature of which will be readily understood as the invention is hereinafter disclosed, my invention consists in the improved construction and combination of parts, hereinafter fully vSo describ'ed, illustrated in the accompanying drawings, and particularly pointed out in the appended claims.

In the accompanying drawings, in which similar reference characters indicate similar parts -in each of the views,-Figure l .is a central vertical sectional view taken through one form of my device." Fig. 2 is a similar viewl taken at right angles tothe section of F'g. 1. Fig. -3 is a horizontal sectional View. Fig. 4 is a top plan view. Fig. 5 is a vertical sectional'vle'w of a modified form.

Fig. 6 is asimilar view of a further modili# cation. Figi. 7 is a plan viewpart ly in section of the construction shown in Fig. 6.

, .j The body-portion4 10 ofmy improved fuse is formed of suitableiinsulating material,

. such asporcelain, glass, etc., and as its exterior threaded-on two planes, as at 11 and 512,each adapted to receive a screw-threaded' metallic ferrule as at 13and 14, respectively,

I as is-common in this type of fuses. In the several modifications ofthe inventmn shown herein, however, the b6dyporti0n is in the lform of a shell, being provided with a-cen-"f tralrecess 15 extending close to thie bottom of the body-portion, leaving a comparatively thin bottom fwall, the annular side wall beingalso relatively, thin, thereby providin .a relatively large recess 'centrally of the bo y`-` portion, rendering the bottom of the plug readily accessible for cleaning or repairing purposes, and at the same timeA providing a large space Within which expansion may `take place when the fuse blows.

The outer threaded ferrule 14 may, if de- 'sired, be in the form of a cap, and I prefer- -ably form the cap with a central opening '16 'and may locate therebelow a transparent plate member or shield 17, although it is not absolutely essential that either be employed.

-I may, if desired, and in the form shown l in Figs. 1- to 4 I prefer so to do, provide the inner wall of the plug with an inclined face 1-8, said face changing the normal circular configuration of the wall of the recess s0 as to prevent' the fuse clamping member from rotating when being secured in position.

The Yseveral views show different ways infuse extends from the top to the bottom'ot the recess, the remaining forms showing the fuse as extending from side to side adjacent the top .of the recess. In each form, however, one ofthe fuse terminals is in the form of a plate 20 located ina slot 21 of the`body portionand having its lower end soldered or otherwise secured to the lower ferrule 13, the upper end of said plate being bent at an angle and extending into the recess as at`22, as 1n Figs. 1, 2, 3, 4, 5 and l, or enlarged as at 22a .in -Fig. 6, the enlargement projecting above the bottom of a lateral slot 23, to re tain the fuse i-n position where it is not given a bend which would tend to weaken it. The

.angular portion 22 or the enlargement 22'a is the fuse in position, and returning the screw ,Y

to position."

Iliithe .forni shown in'Figs. 1 to 4, the oppositeend. of the fuse leads to the bottom ofthe-recess, being clamped underl a metallic lplate 25 by the acti'on of a screw 26 extendrv ing through an opening in the bottom of the .p liig, theinclined face'18 acting to prevent turningofthe plate duringthe securing opgf'eratin.' 'Owing to `the relatively large reinf which .the fuse is located, themanipuof the spring until lation of the `fuse to place it in position or to remove it can be readily had. a positive advantage since it permits of the Eormation of a regulation plug fuse conliguration with, however,v but a minimum number of parts and a maximum space for expansion. i

ln the torni shown in Figs. to 7, the conductor from the screw 2G is in the form ot' a niet-allie plate 27 having lits ends bent in opposite directions. the lower end being secured in position by the screw 26. while the upper end projects into a slot Q8 formed iny the wall of the body-portion opposite the slot Q3. being preferably held in position by screw 29 threaded therethrough into a socket 30 located in a recess 31 at the bottom of the slot 28: as shown in Fig'. 5, the socket mayv be omitted and the threading be directly on the plate 27. ln these forms, the fuse is clamped between the upper end ot' said plate (nhich forms the terminal) and the screw 29, and leads directly across the recess. 'ln these latter types, l may employ a detector in the torni of an element- Sla carried by a screw r other carrier the latter being' normally pressed inwardly by a spring 33 carried by the cap, the element resting on the fuse. and being,l held against the tension the luse blows whereupon the spring causes the element to change its position and thus indicate that the 't'use has b own.

As will be readily seen the constructions shown herein are exceedingly simple and provide for the greatest elliciency in opera#- tion, are formed of a minimum or" parts, can be readily -re-filled when blown. which can be manufactured at a relatively low cost, and which is capable of use with any ot' the standard forms of sockets.

vVhile l have herein shown and described various Ways in which my invention may be carried out, it- Will be readily understood that changes and modifications therein may be required or desired to meet the exigencies of use, and desire it to beimderstood that it reserve the right to make any and all such changes and modiications as long as the same tail Within the spirit and scope ot the invention as expressed in the following claims.

Having; thus described my invention, what lr claim as new is: I

l. in a rellable plug fuse and in combt nation, a body-portion having l a metallic contact exterioriy threaded thereto and heving a central recess, said body-portion also having a slot extending laterally through a wall or said recess adjacent the outer end ot the body-portion inwardly sub` stantialiy paraliel to said recess to a point wat be id the outer piane o1 said Contact, said being depth to piace its cotton@ nation. va body-portion havingT a metallic Contact exteriorly threaded thereto and having a central recess. said body-portion also having a slot extending laterally through a wall ot' said recess adjacent the outer end ot the body-portion and then inwardly substantially parallel to said recess to a point bevond the outer plane oi' said contact. said recess bein.;T oi' a depthito place its bottom beyond the plane oi said slot. a terminal secured to said contact and extending through said slot into said recess. a clamping screw carried b v said terminal. a removable contact screw atthe closed end oi the bodyportion and projecting; into said recess. a plate threaded to said latter screw at the bottom oi the recess. a Jfuse clement ha ving one end secured to said terminal and the other end in electrical connection with said plate. a cap threaded tossaid body-portion, and an indicating device carried by thecap and extending into said recess tor indicating the state oiLl the fuse.

3. In a refillable plug fusennd in combination, a body-portion ha ving a metallic Contact exteriorly threaded thereto and having a central recess. said luidy-portion also having a slot extending laterally through a wali of said recess adjacent the outer end ot the body-portion and then inwardly substantially parallel to said recess to a point beyond the outer plane ot said contact, said recess beingn of a depth to place its bottom beyond the plane of said slot, a terminal secured to said contact and extending through said slot into said recess, a clamping screw carried by said terminal, a removable contact screw at the closed end ot' the bodyportion and projectinginto said recess, a rectangular plate threaded to said latter screw at the bottom ot' the recess, and a fuse element having one end secured to said terminal and the other end in electrical connection with said plate, a wall ot' said recess being oiset to co-act With one edge of the plate to position the iatter against rotative movement.

ALBERT F. DAUM.

Witnesses i2. McCann, H. McCann.

i sise Commissioner of Patents, 

